Calling SQL Functions directly from C#

Question

I have a requirement to run a query against a database that will return either a zero or one (Checking for existance of specific criteria). The Tech specs I\'ve been given for r

Answer 1

This works for me and is based on this answer https://stackoverflow.com/a/3232556/1591831 using a SqlDataAdapter (note that you do not need to use one) and ExecuteScalar (can use ExecuteNonQuery as shown here):

bool res = false;
using (SqlConnection conn = new SqlConnection(GetConnectionString()))
{
    using (SqlCommand comm = new SqlCommand("dbo.MyFunction", conn))
    {
        comm.CommandType = CommandType.StoredProcedure;

        SqlParameter p1 = new SqlParameter("@MyParam", SqlDbType.Int);
        // You can call the return value parameter anything, .e.g. "@Result".
        SqlParameter p2 = new SqlParameter("@Result", SqlDbType.Bit);

        p1.Direction = ParameterDirection.Input;
        p2.Direction = ParameterDirection.ReturnValue;

        p1.Value = myParamVal;

        comm.Parameters.Add(p1);
        comm.Parameters.Add(p2);

        conn.Open();
        comm.ExecuteNonQuery();

        if (p2.Value != DBNull.Value)
            res = (bool)p2.Value;
    }
}
return res;